Indicating counter for firearms



Aug.12, 1941. E. NTHE NDIcATING COUNTER FOR FIREARMS Filed July 2l, 1939 W v.. E N R Wu Tn T..

Patented A'ug12,

INDICATING COUNTER'FOR FIREABMS Erich Nthe, Berlin-Spandau, Germany, assignor to Siemens Apparate Und Maschinen Gesellschaft mit beschrankter Haftung, Berlin, Germany, a corporation of Germany Application July 21, 1939, Serial No. 285,812 In Germany January 1, 1938 6 Claims.

This invention relates to indicating means, and more particularly to means for indicating the number of rounds of ammunition llred from or -available to a gun.

One of the objects of the present invention is to provide means for indicating to a gunner, 1ocated at a pointremote from a gun, the amount of ammunition available to the gun.

Another object of the invention is to provide a novel indicator o1' the above character which is small in size, light in weight, and therefore especially adapted for use aboard aircraft.

A further object is to provide an electrically actuable indicator of the above character which requires only a low voltage.

The above and further objects and novel features will more fully appear from the detailed description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for purposes ofillustration only and is not intended as a definition of the limits of the invention, reference for the latter purpose being had to the appended claims.

In the drawing, wherein like reference characters refer to like parts throughout the several views- Fig. 1 is a side elevation partly in section of one embodiment of the invention;

Fig. 2 is a sectional view taken on line II-II of Fig. l; and

Fig. 3 is a front elevation of the'structure shown in Fig. 1.

The form of the invention. illustrated in the accompanying drawing, by way of example, comprises an indicating device which is especially adapted for indicating at a point remote from a gun the amount of ammunition which is available to or has been nred from the gun, and is constituted by an indicating pointer which moves over a suitable scale and which is attached to a traveling nut, the latter engaging a threaded screw. Means are provided in which potential energy may be stored for normally urging the screw to rotate in one direction, and an escape-l ment mechanism is operatively connected to the screw, which mechanism is controlled by means which operate in vresponse to each iiring of the As shown in Fig. 1 the novel apparatus is constituted bya housing Il having indicator means ment upon the screw. Yielding means are provided for urging the nut axially from an' unthreaded portion of the spindle, as shown in Fig. 1, towards the threaded portion comprising a coil spring l2a which surrounds spindle i3 and is interposed between the nut l2 and a toothed wheel to later appear. A suitable` scale il is provided for the pointer which can be read through a window l5 in the housing i0. The Af scale can be calibrated, for example, in the embodiment shown in accordance with the lnumber A of rounds of ammunition iired from or available to a gun i6 which can be located at some remote point relative to the indicator, the gun being therein comprising a pointer II which is securedto a traveling nutfll, `the latter engaging a threaded spindleor lead screw Il having a bore I la therein, and being adapted tor axial moveconnected to the indicator in a manner to appear laten Means are provided for governing the indicator comprising a step-by-step control arrangement which in the form shown is constituted by an electro-magnet il and an escapement mechanism i8, lIfhis arrangement controls the movement vof the spindle i3 which is normally urged to rotate in a predetermined direction by suitable mechanical means in which potential energy may be stored, for example, a spiral spring I8 .which is disposed Within bore l3a and attached at one extremity thereof to the spindle i3 and at the other extremity to the housing Il.

' The above potential energy means are employed in order that the indicating device can be as compact and light as possible and also in order that it can be controlled by electrically actuable means which require current at a low voltage, i. e., the electro-magnet il and the escapement mechanism.

The .escapement mechanism, in the form shown, comprises toothed escapement wheels 2li, 2| which are mounted upon the spindle in such a manner that the teeth of one wheel are staggered relative to those of the other wheel by an angular amount substantially equal to the width of one tooth. A pawl finger 22 which is adapted for successively engaging the teeth of each wheel is provided which is mounted upon an amature 23 which in turn is pivotally mounted at 2l adjacent electro-magnet I1, and yis normally urged in a counter-clockwise direction by a leaf spring 25.

Manually operable means are provided lor Winding spring I9 and placing the indicator in an initial or zeroA position comprising a gear 26 which is preferably mounted adjacent the inver extremity of spindle Il and which emages a gear 21 secured tothe spindle. Aperti@ o! gear 2l extends through an aperture 26a in the housing ID and can be moved by hand.

The gun i8, which for example may be located in the wing of an aircraft, is operatively connected to the indicator, located for example on the instrument panel of the craft, by means of an intermittently operable electric switch 28 which is preferably actuated by the bolt or lock (not shown) of the gun when in the ready or rear position. Switch 28 is connected to a socket 29 within the housing by means of leads 3D, the socket being connected to the electro-magnet by leads 3 l.

A disc indicator 32 which is visible through a window 33 in the housing face is attached to the armature 23 by means of a bar 3d. The disc provides an indication of the energized or deenergzed condition of the armature il, the disc being visible in the energized condition and not visible or only partially visible as shown in dotted lines in Figure 1 in the deenergized condition. The position of the disc thus makes known to the gunner whether or not the gun is in a ready position for firing or Whether, for example, it is jammed.

In operation, the spindle i3, is rotated by gear 26 in order to wind the spring I9 and to place the pointer il in an initial position at one extremity of the scale I4. When the gun starts firing a current impulse is fed to the electromagnet Il each time the bolt or lock of thegun reaches a predetermined position, e. g., a rear dead center position. This impulse attracts the armature 23 with the result that the pawl 22 is pulled from a tooth gap of the escapement Wheel 2| into an obliquely disposed tooth gap of wheel it, the latter having moved an angular amount equal to the angular difference of said gap, the movement being produced by spring i9. A further rotation of the spindle occurs when the electro-magnet becomes deenergized and the armature 23 is moved back into engagement with wheel 2l under the action of leaf spring 25. With the rotation of the spindle, the pointer H thus progressively advances along the scale I4 in response to the number of rounds of ammunition '.red.

There is thus provided novel means for indicating the number of shots fired from or available to a gun. The apparatus is small, compact, inexpensive to manufacture, and adapted for being controlled by electric means which require only a low voltage. The indicator, moreover, is accurate, dependable and quickly readable.

Although only one embodiment of the present invention has been illustrated and described in detail,-it is to be expressly understood that the invention is not limited thereto. For example, instead of operatively interconnecting the gun and the indicator by electrically operable means, it is possible to mechanically interconnect them. Further, the novel indicator is not restricted to use with a gun but may be employed for indicating any quantity which changes in response to intermittent impulses. Various changes may be made in the design and arrangement of the parts without departing from the spirit and scope of theinvention as the same will now be understood by those skilled in the art. For a, definition of the limits of the invention, reference will be had primarilyto the appended claims.

What is claimed is:

1. 'Ifhe combination with a pointer, of a spindle having a threaded portion and an unthreaded portion, a traveling nut for the spindle initially disposed above the threaded portion, yieldable means mounted on said spindle about the un.- threaded portion thereof for urging said travelling nut toward the threaded portion, the pointer being mounted on the nut, a scale for the pointer, the scale being mounted upon a housing, intermittently operable escapement mechanism operatively connected to said spindle, and a spring coaxial with the spindle and coupled thereto, the spring also being attached to the housing.

2. In apparatus of the class described, a lead screw, a nut upon said screw, a pointer attached to the nut, an escapement mechanism for said screw comprising a rst escapement gear secured to said screw, a second escapement gear coaxial with the iirst gear and secured to said screw, the teeth of the two gears being angularly displaced relative to one another by a predetermined amount, and a pivotally mounted pawl adapted for movement from one gear to the other, and means for oscillating said pawl.

3. In apparatus of the class described, a spindle having a bore therein, a traveling nut engaging the spindle, a pointer attached to said nut, escapement means operatively connected to the spindle for controlling movement of the spindle, means for actuating the last named means, yieldable means mounted within said bore and adapted for moving said spindle and manually operative means for tensioning said yieldable means.

4. In apparatus of the class described, a lead screw having a bore therein, a nut engaging said screw, a pointer secured to said nut, a scale for said pointer, escapement means operatively connected to said screw for controlling movement of said screw in predetermined angular increments, yieldable means mounted within said bore for moving said lead screw, and manually movable means for rotating said screw to an initial position, said yieldable means being placed in a constrained condition when said manually movable means moves the screw to said initial posiion.

5. In apparatus of the class described, a housing, a spindle mounted for rotatable movement Within said housing, an index operatively associated with the spindle, energy storing means comprising a coiled member operatively connected with said spindle for rotating the spindle, escapement means for controlling the amount of rotation of said spindle, manually operative means for energizing said energy storing means and moving said index to an initial position, and a scale exposed by said housing, said index moving adjacent said scale during rotation of said spindle.

6. In apparatus of the class described, a housing, a spindle having a hollow bore mounted for rotatable movement Within said housing, an index carried by said spindle for axial movement thereon, a coiledspring within said spindle bore for rotating the spindle, escapement mechanism for controlling the amount of rotation of said spindle, manually operative means for rotating said spindle and tensioning said coiled spring .whereby said index is moved to an initial position,

and a scale carried by said housing, said index moving adjacent said scale during rotation of said spindle.

ERICH NTHE. 

